Gene writes –

Have you ever dreamed of having one of those replicators from Star Trek? Ever wanted to make just about anything at the flip of a switch? Well guess what? You’re in luck, because in this Instructable I will show you how to make the closest thing to a replicator that current technology can manage; a 3D printer. Wait a minute, isn’t there another Instructable on how to make a 3D printer from Legos? Yep, there is, but this 3D printer is different; it’s a polar 3D printer and it’s capable of printing out so much more than just chocolate. Now at this point in the intro you’re probably thinking what do I mean by polar 3D-printer. Is it a 3D-printer that only works in the in the polar regions? A polar printer is a printer whose principal axes, or how it can move, are radius(in and out), angle(spin clockwise/counter clockwise), and as opposed to a Cartesian printer whose principal axes are X(left/right), Y(up/down). In other words, it moves just like a polar coordinate system.

HOW TO – Build a Polar 3-D printer from LEGO – Link.